Abstract: A semiconductor device includes an N-type silicon carbide substrate, an N-type silicon carbide layer formed on the N-type silicon carbide substrate, a P-type region selectively formed in a surface layer of the N-type silicon carbide layer, an N-type source region formed in the P-type region, a P contact region formed in the P-type region, a gate insulating film formed on a portion of a region from the N-type source region, through the P-type region, to the N-type silicon carbide layer, a gate electrode formed on the gate insulating film, an interlayer insulating film covering the gate electrode, and a first source electrode electrically connected to a surface of the P contact region and the N-type source region. An end of the interlayer insulating film covering the gate electrode has a slope of a predetermined angle.

Abstract: In a first main surface side of a silicon carbide semiconductor base, a trench is formed. A second base region of a second conductivity type is arranged at a position facing the trench in a depth direction. An end (toward a drain electrode) of the second base region of the second conductivity type, and an end (toward the drain electrode) of a first base region of the second conductivity type reach a position deeper than an end (toward the drain electrode) of a region of a first conductivity type. Thus, the electric field at a gate insulating film at the trench bottom is mitigated, suppressing the breakdown voltage of the active region and enabling breakdown voltage design of the edge termination region to be facilitated. Further, such a semiconductor device may be formed by an easy method of manufacturing.

Abstract: A semiconductor device includes: an n+-type drain region made of a wide-bandgap semiconductor material; an n-type epitaxial layer provided on the top surface of the drain region; an n-type first semiconductor region provided at an upper portion of the epitaxial layer and having a higher impurity concentration than the epitaxial layer; an n-type second semiconductor region provided on the first semiconductor region and having a higher impurity concentration than the first semiconductor region; p-type base regions surrounding to include an upper portion in the middle of the second semiconductor region; n-type source regions provided at upper portions of the base regions to form a channel; and a gate electrode which controls a surface potentials of the channels.

Abstract: A semiconductor device includes an n+-type source region having an impurity concentration higher than that of an n-type source region, formed in a surface layer of a p-type SiC layer and a p-type base region, farther on an outer side than the n-type source region, and contacting the n-type source region; an n-type region and an n+-type region having an impurity concentration higher than that of the n?-type SiC layer, formed in a portion of the n?-type SiC layer between p-type base regions and p-type SiC layers; and a second n-type region under the p-type base region and of a size smaller than that of the p-type base region, whereby low on-resistance and precision of the threshold voltage Vth are enhanced, increasing quality and enabling improved resistance to dielectric breakdown of the gate insulating film and resistance to breakdown.

Abstract: A trench gate structure vertical MOSFET includes a silicon carbide substrate of a first conductivity type, a first semiconductor layer of the first conductivity type, a second semiconductor layer of a second conductivity type, first semiconductor regions of the first conductivity type, a trench, a gate electrode, an interlayer insulating film, a barrier layer, a contact electrode, a first electrode, and a second electrode. The barrier layer includes a layer made of TiN, and the thickness of the TiN layer is 10 to 80 nm. The interlayer insulating film is a laminate film of non-doped silicate glass and borophosphosilicate glass.

Abstract: A p-type region, a p? type region, and a p+ type region are selectively disposed in a surface layer of a silicon carbide substrate base. The p-type region and the p? type region are disposed in a breakdown voltage structure portion that surrounds an active region. The p+ type region is disposed in the active region to make up a JBS structure. The p? type region surrounds the p-type region to make up a junction termination structure. A Schottky electrode forms a Schottky junction with an n-type silicon carbide epitaxial layer. The Schottky electrode overhangs an interlayer insulation film covering a portion of the p-type region and this overhanging portion acts as a field plate. The p+ type region has an acceptor concentration greater than or equal to a predetermined concentration and can make a forward surge current larger.

Abstract: A semiconductor device includes on an n-type semiconductor substrate of silicon carbide, an n-type semiconductor layer, a p-type base region, an n-type source region, a p-type contact region, a gate insulating film, a gate electrode, and a source electrode. The semiconductor device has a drain electrode on a back surface of the semiconductor substrate. On a surface of the gate electrode, an interlayer insulating film is disposed. The interlayer insulating film has plural layers among which, one layer is formed by a silicon nitride film. With such a structure, degradation of semiconductor device properties are suppressed. Further, increases in the number of processes at the time of manufacturing are suppressed.

Abstract: A semiconductor device of an embodiment includes a p+-type region selectively disposed in a surface of an n-type silicon carbide epitaxial layer disposed on an n+-type silicon carbide substrate, an element structure that includes a source electrode and a p+-type region that form a metal-semiconductor junction on the n-type silicon carbide epitaxial layer, a p?-type region and another p?-type region that surround the periphery of the element structure, and an n+-type channel stopper region that surrounds the periphery of the p?-type regions so that the n-type silicon carbide epitaxial layer is therebetween. The n+-type channel stopper region has a second n+-type channel stopper region whose impurity concentration is high, and a first n+-type channel stopper region that encompasses the second n+-type channel stopper region and whose impurity concentration is lower than that of the second n+-type channel stopper region.

Abstract: An active region through which current flows in a semiconductor device includes an n?-type silicon carbide epitaxial layer formed on a front surface of an n+-type silicon carbide semiconductor substrate; a p-type layer becoming a channel region; a trench formed so as to be in contact with a p-type layer and having an oxide film and a gate electrode embedded therein; a p+-type layer arranged beneath the trench and between trenches; an n?-type layer in contact with the p-type layer, a p+-type layer, and the trench, and arranged in contact with a p+-type layer or on a surface side of the semiconductor substrate; an n-type layer in contact with the n?-type silicon carbide epitaxial layer and the p+-type layer, and having an impurity concentration higher than that of the n?-type layer and that of the n?-type silicon carbide epitaxial layer.

Abstract: In a first main surface of a silicon carbide semiconductor base, a trench is formed. On a first main surface side of the silicon carbide semiconductor base, an n-type silicon carbide epitaxial layer is deposited. In a surface of the n-type silicon carbide epitaxial layer, an n-type high-concentration region is provided. In the surface of the n-type silicon carbide epitaxial layer, a first p-type base region and a second p+-type base region are selectively provided. The second p+-type base region is formed at the bottom of the trench. A depth of the n-type high-concentration region is deeper than that of the first p-type base region and the second p+-type base region. Thus, by an easy method, the electric field at a gate insulating film at the bottom of the trench is mitigated, enabling the breakdown voltage of the active region to be maintained and the ON resistance to be lowered.

Abstract: In a first main surface side of a silicon carbide semiconductor base, a trench is formed. A second base region of a second conductivity type is arranged at a position facing the trench in a depth direction. An end (toward a drain electrode) of the second base region of the second conductivity type, and an end (toward the drain electrode) of a first base region of the second conductivity type reach a position deeper than an end (toward the drain electrode) of a region of a first conductivity type. Thus, the electric field at a gate insulating film at the trench bottom is mitigated, suppressing the breakdown voltage of the active region and enabling breakdown voltage design of the edge termination region to be facilitated. Further, such a semiconductor device may be formed by an easy method of manufacturing.

Abstract: A silicon carbide semiconductor device, including a silicon carbide substrate, a drift layer provided on a front surface of the silicon carbide substrate, an embedded layer selectively provided in a surface layer of the drift layer, an epitaxial layer provided on the drift layer, a channel layer provided on the epitaxial layer, a source region selectively provided in a surface layer of the channel layer, a trench penetrating the source region and the channel layer and reaching the epitaxial layer, a gate electrode provided in the trench via a gate insulating film, a source electrode in contact with the channel layer and the source region, and a drain electrode provided on a rear surface of the silicon carbide substrate. The embedded layer is arranged underneath the trench in a depth direction. A longitudinal direction of the trench, which is perpendicular to the depth direction, is parallel to the off-direction of the silicon carbide substrate.

Abstract: A semiconductor device includes a wide-bandgap semiconductor substrate of a first conductivity type, a wide-bandgap semiconductor layer of the first conductivity type provided on a front surface of the wide-bandgap semiconductor substrate of the first conductivity type, a base region of a second conductivity type selectively provided in a surface layer of the wide-bandgap semiconductor layer of the first conductivity type, and a trench having a striped planar pattern. The base regions are cyclically provided in a direction parallel to the trench. At the lower portion of the trench, a portion of the base region extends in a direction parallel to the trench and the base regions are connected to each other.

Abstract: A semiconductor device includes an active region provided in an n+-type silicon carbide substrate and through which main current flows, a termination region that surrounds a periphery of the active region, and a p-type silicon carbide layer provided on a front surface of the n+-type silicon carbide substrate and extending into the termination region. A region of the p-type silicon carbide layer extending into the termination region includes one or more step portions that progressively reduce a thickness of the p-type silicon carbide layer as the p-type silicon carbide layer becomes farther outward from the active region.

Abstract: A semiconductor device including a semiconductor substrate of a first conductivity type, a plurality of base regions of a second conductivity type formed on a first principal surface of the semiconductor substrate via a semiconductor layer of the first conductivity type, and a plurality of source regions of the first conductivity type formed in the base regions. Each base region, in a top-down view from an angle perpendicular to the first principle surface, is of a polygonal shape. Each adjacent two of the base regions in the top-down view have two sides, one from each of the two base regions, that face each other across a portion of the semiconductor layer, the source region being formed at only one of the two sides.

Abstract: A semiconductor device includes a silicon carbide semiconductor substrate, a first silicon carbide layer of a first conductivity type, a first semiconductor region of a second conductivity type, a second semiconductor region of the first conductivity type, a third semiconductor region of the second conductivity type, a gate insulating film, a gate electrode, an interlayer insulating film, a source electrode, and a drain electrode. The third semiconductor region is thicker than the second semiconductor region and a width of a side of the third semiconductor region facing the first semiconductor region is narrower than a width of a side thereof facing the source electrode.

Abstract: A gate trench of a MOS gate formed in the front surface of a silicon carbide substrate includes a first portion that includes the bottom surface of the gate trench, a second portion that is connected to the substrate front surface side of the first portion, and a third portion that is connected to the substrate front surface side of the second portion. In the third portion of the gate trench, an n+ source region is exposed along the sidewalls. The width of the third portion of the gate trench is greater than the widths of the first and second portions and of the gate trench. Upper corners of the gate trench smoothly connect the sidewalls to the substrate front surface. The thickness of a gate insulating film smoothly connected along the bottom surface and sidewalls of the gate trench is substantially uniform over the entire inner wall surface of the gate trench.

Abstract: A MOS gate is provided on a front surface side of a silicon carbide substrate. The silicon carbide substrate includes silicon carbide layers sequentially formed on an n+-type starting substrate by epitaxial growth. Of the silicon carbide layers, a p+-type silicon carbide layer is a p+-type high-concentration base region and is separated into plural regions by a trench. A p-type silicon carbide layer among the silicon carbide layers covers the p+-type silicon carbide layer and is embedded in the trench. A p-type silicon carbide layer among the silicon carbide layers is a p-type base region. From a substrate front surface, a gate trench penetrates the p-type base region in the trench and the n+-type source region to reach an n?-type drift region. Between the p+-type high-concentration base region and a gate insulating film at a sidewall of the gate trench, the p-type base region is embedded in the trench.

Abstract: A MOS gate having a trench gate structure is formed on the front surface side of a silicon carbide substrate. A gate trench of the trench gate structure goes through an n+ source region and a p-type base region and reaches an n? drift region. Between adjacent gate trenches, a first p+ region that goes through the p-type base region in the depth direction and reaches the n? drift region is formed at a position separated from the gate trenches. The first p+ region is formed directly beneath a p++ contact region. The width of the first p+ region is less than the width w1 of the gate trench. A second p+ region is formed at the bottom of the gate trench. The first and second p+ regions are silicon carbide epitaxial layers.

Abstract: A semiconductor device includes in an active region in which current flows, an n+-type silicon carbide epitaxial layer of a low concentration and formed on an n+-type silicon carbide substrate; a p-type channel region constituting a channel region; a trench contacting the p-type channel region and having embedded therein an oxide film and a gate electrode; a p+-type base layer arranged beneath the trench; a third n-type CSL layer region contacting the p-type channel region; a second n-type CSL layer region having a maximum impurity concentration higher than that of the third n-type CSL layer region, the maximum impurity concentration being farther on a substrate front side than a top of the p+-type base layer arranged beneath the trench is; and a first n-type CSL layer region contacting the second n-type CSL layer region and having a maximum impurity concentration lower than that of the second n-type CSL layer region.